1. Field of the Invention
The present invention relates to a color picture tube apparatus used in a TV, a computer display, or the like.
2. Description of the Related Art
In terms of the recent global environmental protection movement and the like, the energy savings in electrical products are being promoted. Even in a color picture tube apparatus, energy-saving technology based on deflection power is being introduced.
In order to reduce deflection power, for example, JP2003-208859A describes a deflection yoke as shown in FIG. 7. FIG. 7 is a partial cross-sectional view of the deflection yoke along a surface vertical to a tube axis. In FIG. 7, an X-axis represents a horizontal axis, and a Y-axis represents a vertical axis. The deflection yoke 100 includes an insulating frame 101, a pair of upper and lower saddle-type horizontal deflection coils 102 provided on an inner surface side of the insulating frame 101, a pair of right and left saddle-type vertical deflection coils 103 provided on an outer surface side of the insulating frame 101, and a core 104 covering an outer surface side of the saddle-type vertical deflection coils 103. Reference numeral 2 denotes a funnel of a color picture tube. A pair of upper and lower magnetic substance projections 104a are provided in the vicinity of positions of an inner surface of the core 104 where the Y-axis crosses. The pair of upper and lower magnetic substance projections 104a extend through between the pair of right and left saddle-type vertical deflection coils 103, and project to the vicinity of the pair of upper and lower saddle-type horizontal deflection coils 102. This enables each top portion of the pair of upper and lower magnetic substance projections 104a to be close to a deflection region of an electron beam. Therefore, the magnetic resistance of a horizontal deflection magnetic field can be decreased, and the horizontal deflection magnetic field in the deflection region can be intensified. Consequently, deflection power can be reduced.
In the above-mentioned conventional deflection yoke 100, as the horizontal width W0 of the pair of upper and lower magnetic substance projections 104a is increased, the effect of reducing the deflection power is increased. However, when the horizontal width W0 is increased, there are the following problems: a horizontal interval between the pair of right and left saddle-type vertical deflection coils 103 is enlarged so as to avoid the interference with respect to the magnetic substance projections 104a, and a barrel magnetic field of a vertical deflection magnetic field is intensified more than necessary, whereby a misconvergence and raster distortion occur.
More specifically, in the above-mentioned conventional deflection yoke, it is difficult to further reduce horizontal deflection power while forming a barrel magnetic field capable of realizing a satisfactory convergence and raster.